Sudden sensorineural hearing loss (SSHL), or sudden deafness, is a rapid, unexplained loss of hearing that develops suddenly or over a period of several days. The three important statistics below can help shed light on SSHL and what to do if you experience a sudden hearing loss.

1. Various studies estimate that sudden sensorineural hearing loss affects between 5-30 people per 100,000 each year.

2. The NIDCD estimates that only 10 to 15 percent of patients have their sudden sensorineural hearing loss traced to a specific cause.

Dr. Mark Syms explains that the specific causes of SSHL have been studied in the hearing organ of patients who have later passed away. “For a patient in front of me seeking care, I can’t know [the cause] because the only way I would be able to know that is to take the hearing organ out of their head,” he says.

Meaning: the only way this is accomplished is if you’re already dead.

3. The majority of SSHL patients — roughly 9 out of 10 — lose hearing in only one ear.

The only way to accurately diagnose the severity and cause of hearing loss is to have a hearing exam administered.